Stutz



March 10, 1964 K. STUTZ 3,124,723

METHOD FOR THE AUTOMATIC SELECTION OF THE SPEED OF ESCALATORS Filed June5, 1959 United States Patent Ofiice 3,124,723 Patented Mar. 10, 19643,124,723 METHOD FOR THE AUTOMATIC SELECTION OF THE SPEED OF ESCALATORSKarl Stutz, Hinterbramberg 6, Lucerne, Switzerland Filed June 3, 1959,Ser. No. 817,930 Claims priority, application Switzerland June 5, 195811 Claims. (Cl. 317-142).

This invention relates to a method for the automatic selection of thespeed, adapted to the frequency of the passengers, of escalators, and toa device for carrying out the method.

It is known to set escalators in operation automatically on the approachof passengers, by means of floor contacts or light barriers. Two-speeddrive arrangements have also already been proposed for escalators,wherein the increased speed is switched on by a switch clock at withincreased .traflic.

Furthermore escalators have already been equipped withpassenger-counting arrangements, for statistical purposes, wherein forexample a cam moved by a roller of the loaded steps directly actuates amechanical counting mechanism, or actuates, through a contact, anelectrical impulse-counting mechanism.

' Now the invention relates to a method for the auto matic selection ofthe speed, adapted to the sfirequency of the passengers, of escalators,in which method, according to the passenger frequency at the givenmoment, the lower or higher conveying speed is selected automatically.According to the invention the impulses instigated by the passengersserve for the measurement of the frequency. The novelty according to theinventionconsists in that the duration of time between two passengerimpulses or the frequency of the number of passengers is compared with apredetermined, settable, normal value, whereupon, in dependence upon thedeparture of the compared values, a switch command is issued for thelower or higher speed.

The device for carrying out the method is characterised in that ameasuring arrangement is provided, which measures the duration of timebetween two impulses or the frequency of the passengers, and comparesthis with a settable, critical value, and further in that a switcharrangement is provided, which varies the conveying speed in dependenceupon the difference between the two compared values.

An example of embodiment of the inventon is illustrated by reference toa circuit diagram in the accompanying drawing.

In the drawing, and designate the poles of a source of direct current.Between these poles there are interposed an impulse contact 1 and arelay 2. The impulse contact 1 has .a trigger device (not shown), whichis installed in the escalator and is interrupted for a short time byevery person using the escalator. It can be actuated for example by aroller of the loaded escalator step. The relay 2 possesses an offcontact 2.1 and a switch-over contact 2.2. Connected in parallel withthe impulse contact 1 and the relay 2 there is a gas-tilled relay tube 3with anode 12, cold cathode 13 and starter electrode 14, the oifcontact2.1 being connected into the anode lead 15 and a resistance 6 beingconnected into the cathode lead 16. "The switch-over contact 2.2 isconnected through a lead v17 with the starter electrode 14. Furthermorea variable resistance is inserted into the current circuit of theswitch-over contact 2.2. 4 designates a condenser, through which thestarter electrode is connected with the pole.

The cathode lead 16 is connected through a variable resistance 7 withthe grid 18 of a negatively biassed vacuum triode 10, the anode 19 ofwhich is connected through a relay 1-1 with the pole of the source ofdirect current and the cathode 20 of which is connected through aresistance 9 with the pole of the source of direct current. A condenser8 is connected between the grid 18 and this negative pole of the source.The relay 11 possesses a switch-over contact 11.1, through which,according to choice, a coil 12 or "13" of a relay switch is energised.The coil 12 serves for switching on the high conveying speed and thecoil 13' for switching on the low conveying speed.

The condenser 4, with the variable resistance 5, forms a settable timenorm, while the R-C member consisting of the variable resistance 7 landthe condenser 8 serves for the delaying of the switch-over of the speedson variation of the passenger frequency.

The arrangement as described works as follows: Every time a passengerpasses the measuring point, the impulse contact 1 imparts an impulse tothe relay 2, whereupon the contacts 2.1 and 2.2 are shifted over for ashort time. The condenser 4 is then discharged to zero potential,whereby the anode circuit of the relay tube 3 is interrupted. The relaytube 3, if lit up, is thereby extinguished. Thus the time norm is setback to the zero position. After the impulse the condenser 4 is chargedup afresh through the resistance 5. When its potential has reached thevalue of the lighting potential of the starter electrode of the tube 3,the latter lights up. This time is used as time norm, and is set toabout 2 seconds, corresponding to a mean passenger frequency. If thefrequency is higher, an impulse follows a preceding one beiiore the tube3 lights up, so that the tube 3 never lights up at all. Thus the voltagedrop on the resistance 6 is always zero also.

If the passenger frequency is low, the tube lights up periodically, andrectangular impulses occur on the resistance 6, which impulses are thelonger in relation to the period duration, the lower is the passengerfrequency. On the condenser 8 there occurs a voltage equal to the meanvalue of these rectangular impulses. Thus this voltage is a measure forthe deviation orf the time duration between two passenger impulses andthe time norm. It controls the current in the vacuum triode 10, which isnegatively biasse-d by the resistance 9. The relay 11 pulls up at acertain voltage on the condenser 8, or drops off when this certainvoltage is not reached. When pulled up it switches on the relay switch13' for the low travelling speed, and when dropped off it switches onthe switch 12'. for the high speed.

By the resistance 7 the change-over of the speed on variation of thepassenger frequency can be delayed by a settable time.

.Instead of .the R-C combination 4, 5 the time norm can also beestablished through an electromechanical relay with predeterminablydelayed action for controlling the igniting of the tube 3.

What I claim is:

1. An arrangement for automatically varying the speed of an escalatorbetween predetermined values, depending upon the passenger frequency,comprising, in combination, relay switch means movable by energizationbetween a normal and an alternative position and adapted to beoperatively connected with the escalator and to cause, when in saidnormal position, escalator operation at a predetermined speed, and tocause, when in said alternative position, escalator operation at apredetermined lower speed; circuit means including a source of electricenergy and normally open main contact means positioned and adapted to beactuated once for every passenger traveling on the escalator; and timecomparator means controllable by closing of said main contact means andincluding a timing circuit establishing a predetermined reference timeperiod, for comparing the actual intervals between consecutiveactuations of said main contact means with said predetermined referencetime period, and for delivering an energizing voltage to said relayswitch means so as to move the latter to said alternative position onlywhen said actual intervals are longer than said predetermined referencetime period.

2. An arrangement for automatically controlling two switch devicesadapted to be connected with an escalator and to vary the speed thereofbetween predetermined values, depending upon the passenger frequency,comprising, in combination, a first relay switch adapted to cause, whenenergized, operation of the escalator connected therewith at apredetermined speed; a second relay switch adapted to cause, whenenergized, operation of the escalator connected therewith at apredetermined lower speed; circuit means including a source of electricenergy and normally open main contact means positioned and adapted to beactuated and closed for a brief moment once for every passengertraveling on the escalator; first switch means in circuit with saidsource and operatively connected with said main contact means andincluding timing means for delivering a control voltage pulse only apredetermined reference time period after actuation of said main contactmeans, but incapable of delivering said control voltage pulse if saidactuation occurs after a preceding actuation before the end of saidpredetermined reference time period; second switch means controllable bysaid control voltage pulses for connecting, upon application of saidcontrol voltage pulses, a source of electric energy with said secondrelay switch so as to energize the latter, and for connecting, whendeenergized, said source with said first relay switch so as to energizethe latter, so that when the passenger frequency is small said controlvoltage pulses are delivered and said second relay switch operates tocause said predetermined lower escalator speed, while when the passengerfrequency is higher and the intervals between actuations of said maincontact means are shorter than said reference time period, no controlvoltage pulse is delivered and said first relay switch operates to causesaid predetermined higher escalator speed.

3. An arrangement as claimed in claim 2, wherein said first switch meanscomprises a relay tube having a starter electrode, an anode and acathode, a time relay means having a coil connected to be energized byclosing said main contact means, and a timing condenser connected incircuit with said starter electrode, said time relay means causing, whendeenergized, charging of said timing condenser and ignition of said tubewhen said condenser, a predetermined reference time period afteractuation of said main contact means, is charged to the ignitionpotential of said tube, and said time relay means causing, when brieflyenergized, discharge of said timing condenser and non-conductivity ofsaid tube.

4. An arrangement as claimed in claim 3, wherein said first switch meanscomprise an adjustable resistor in series with said condenser foradjusting the charging rate thereof.

5. An arrangement as claimed in claim 2, wherein said second switchmeans comprise a triode and control relay means controllable by theoutput of said triode, the control grid of said triode being connectedwith said relay tube to be controlled by a control voltage derivedtherefrom when said relay tube is condutcive, and a capacitor beingconnected in the circuit between said triode and said relay tube forrendering said control voltage depending upon the ratio between theintervals separating said control voltage pulses and said predeterminedreference time period, said control relay means causing, when energized,energization of said second relay switch, and causing, when deenergized,energization of said first relay switch.

6. An arrangement as claimed in claim 5, wherein a variable time delaymeans is connected between said relay tube and said triode.

7. An arrangement as claimed in claim 6, wherein said variable timedelay means is a variable resistor.

8. An arrangement for automatically varying between predetermined valuesthe speed of conveyor means carrying objects along a predetermined path,depending upon the conveyed object frequency, comprising, incombination, relay switch means movable by energization between a normaland an alternative position and adapted to be operatively connected withthe conveyor means and to cause, when in said normal position, operationof said conveyor means at a predetermined speed, and to cause, when insaid alternative position, operation of said conveyor means at apredetermined lower speed; circuit means including a source of electricenergy and normally open main contact means positioned and adapted to beactuated once for every individual object being conveyed by saidconveyor means; and time comparator means controllable by closing ofsaid main contact means and including a timing circuit establishing apredetermined reference time period, for comparing the actual intervalsbetween consecutive actuations of said main contact means with saidpredetermined reference time period, and for delivering an energizingvoltage to said relay switch means so as to move the latter to saidalternative position only when said actual intervals are longer thansaid predetermined reference time period.

9. An arrangement for automatically controlling two switch devicesadapted to be connected with a conveyor means carrying objects along apredetermined path and to vary the speed thereof between predeterminedvalues, depending upon the conveyed object frequency, comprising, incombination, a first relay switch adapted to cause, when energized,operation of the conveyor means connected therewith at a firstpredetermined speed; a second relay switch adapted to cause, whenenergized, operation of the conveyor means connected therewith at asecond predetermined lower speed; circuit means including a source ofelectric energy and normally open main contact means positioned andadapted to be actuated and closed for a brief moment once for everyindividual object being conveyed by said conveyor means; first switchmeans in circuit with said source and operatively connected with saidmain contact means and including timing means for delivering a controlvoltage pulse only a predetermined reference time period after actuationof said main contact means, but incapable of delivering said controlvoltage pulse if said actuation occurs after a preceding actuationbefore the end of said predetermined reference time period; secondswitch means controllable by said control voltage pulses for connecting,upon application of said control voltage pulses, a source of electricenergy with said second relay switch so as to energize the latter, andfor connecting, when deenergized, said source with said first relayswitch so as to energize the latter, so that when the conveyed objectfrequency is small said control voltage pulses are delivered and saidsecond relay switch operates to cause said second predetermined lowerconveyor speed, while when the conveyed object frequency is higher andthe intervals between actuations of said main contact means are shorterthan said reference time period, no control voltage pulse is deliveredand said first relay switch operates to cause said first predeterminedconveyor speed.

10. An arrangement for automatically controlling two switch devicesadapted to be connected with an escalator and to vary the speed thereofbetween predetermined values, depending upon the passenger frequency,comprising, in combination, a first relay switch adapted to cause, whenenergized, operation of the escalator connected therewith at apredetermined speed; a second relay switch adapted to cause, whenenergized, operation of the escalator connected therewith at apredetermined lower speed; circuit means including a source of electricenergy and normally open main contact means positioned and adapted to beactuated and closed for a brief moment once for every passengertraveling on the escalator; first switch means in circuit with saidsource and operatively connected with said main contact means andincluding timing means for delivering a control voltage pulse only apredetermined reference time period after actuation of said main contactmeans, but incapable of delivering said control voltage pulse if saidactuation occurs after a preceding actuation before the end of saidpredetermined reference time period, said first switch means comprisinga relay tube having a starter electrode, an anode and a cathode, a timerelay means having a coil connected to be energized by closing said maincontact means, and a timing condenser connected in circuit with saidstarter electrode, said time relay means causing, when deenergized,charging of said timing condenser and ignition of said tube when saidcondenser, a predetermined reference time period after actuation of saidmain contact means, is charged to the ignition potential of said tube,and said time relay means causing, when briefly energized, discharge ofsaid timing condenser and non-conductivity of said tube, said firstswitch means further comprising an adjustable resistor in series withsaid condenser for adjusting the charging rate thereof, said time relaymeans having a first normally closed relay contact in the anode circuitof said tube, and a change-over contact connected between the terminalsof said source, said timing condenser and said adjustable resistor insuch a manner that, when said time relay means is deenergized, saidtiming condenser and adjustable resistor are connected in series betweensaid terminals so that said condenser is charged, while, when said timerelay means is briefly energized, said condenser is discharged and saidanode circuit is interrupted so as to extinguish said tube; secondswitch means controllable by said control voltage pul es for connecting,upon application of said control voltage pulses, a source of electricenergy with said second relay switch so as to energize the latter, andcon necting, when deenergized, said source with said first relay switchso as to energize the latter, so that when the passenger frequency issmall said control voltage pulses are delivered and said second relayswitch operates to cause said predetermined lower escalator speed, whilewhen the passenger frequency is higher and the intervals betweenactuations of said main contact means are shorter than said referencetime period, no control vol age pulse is delivered and said first relayswitch operates to cause said predetermined higher escalator speed.

11. An arrangement as claimed in claim 10, wherein said second switchmeans comprise a triode and control relay means controllable by theoutput of said triode, the control grid of said triode being connectedwith said relay tube to be controlled by a control voltage derivedtherefrom when said relay tube is conductive, and a capacitor beingconnected in the circuit between said triode and said relay tube forrendering said control voltage dependent upon the ratio between theintervals separating said control voltage pulses and said predeterminedreference time period, said control relay means causing, when energized,energization of said second relay switch, and causing, when deenergized,energization of said first relay switch.

References Cited in the file of this patent UNITED STATES PATENTS1,985,563 FitzGerald Dec. 25, 1934 2,567,928 Farmer Sept. 18, 19512,602,888 Audier July 8, 1952 2,650,301 Farmer Aug. 25, 1953

1. AN ARRANGEMENT FOR AUTOMATICALLY VARYING THE SPEED OF AN ESCALATORBETWEEN PREDETERMINED VALUES, DEPENDING UPON THE PASSENGER FREQUENCY,COMPRISING, IN COMBINATION, RELAY SWITCH MEANS MOVABLE BY ENERGIZATIONBETWEEN A NORMAL AND AN ALTERNATIVE POSITION AND ADAPTED TO BEOPERATIVELY CONNECTED WITH THE ESCALATOR AND TO CAUSE, WHEN IN SAIDNORMAL POSITION, ESCALATOR OPERATION AT A PREDETERMINED SPEED, AND TOCAUSE, WHEN IN SAID ALTERNATIVE POSITION, ESCALATOR OPERATION AT APREDETERMINED LOWER SPEED; CIRCUIT MEANS INCLUDING A SOURCE OF ELECTRICENERGY AND NORMALLY OPEN MAIN CONTACT MEANS POSITIONED AND ADAPTED TO BEACTUATED ONCE FOR EVERY PASSENGER TRAVELING ON THE ESCALATOR; AND TIMECOMPARATOR MEANS CONTROLLABLE BY CLOSING OF SAID MAIN CONTACT MEANS ANDINCLUDING A TIMING CIRCUIT ESTABLISHING A PREDETERMINED REFERENCE TIMEPERIOD, FOR COMPARING THE ACTUAL INTERVALS BETWEEN CONSECUTIVEACTUATIONS OF SAID MAIN CONTACT MEANS WITH SAID PREDETERMINED REFERENCETIME PERIOD, AND FOR DELIVERING AN ENERGIZING VOLTAGE TO SAID RELAYSWITCH MEANS SO AS TO MOVE THE LATTER TO SAID ALTERNATIVE POSITION ONLYWHEN SAID ACTUAL INTERVALS ARE LONGER THAN SAID PREDETERMINED REFERENCETIME PERIOD.